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arXiv · 1702.00206

Non-standard hierarchies of the runnings of the spectral index in inflation

Chris Longden
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Abstract

Recent analyses of cosmic microwave background surveys have revealed hints that there may be a non-trivial running of the running of the spectral index. If future experiments were to confirm these hints, it would prove a powerful discriminator of inflationary models, ruling out simple single field models. We discuss how isocurvature perturbations in multi-field models can be invoked to generate large runnings in a non-standard hierarchy, and find that a minimal model capable of practically realising this would be a two-field model with a non-canonical kinetic structure. We also consider alternative scenarios such as variable speed of light models and canonical quantum gravity effects and their implications for runnings of the spectral index.

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Chris Longden. 2017-02-01. Non-standard hierarchies of the runnings of the spectral index in inflation. https://doi.org/10.3390/universe3010017

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